//*****************************************************************************
// Copyright 2017-2019 Intel Corporation
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//*****************************************************************************

#pragma once

#include "ngraph/op/op.hpp"

namespace ngraph
{
    namespace op
    {
        namespace util
        {
            // clang-format off
            /// \brief Abstract base class for elementwise unary arithmetic operations, i.e.,
            ///        operations where the same scalar arithmetic operation is applied to each
            ///        element.
            ///
            /// For example, if the underlying operation (determined by the subclass) is
            /// \f$\mathit{op}(x)\f$, the input tensor \f$[[x,y],[z,w]]\f$ will be mapped to
            /// \f$[[\mathit{op}(x),\mathit{op}(y)],[\mathit{op}(z),\mathit{op}(w)]]\f$.
            ///
            /// ## Inputs
            ///
            /// |       | Type                              | Description                                                              |
            /// | ----- | --------------------------------- | ------------------------------------------------------------------------ |
            /// | `arg` | \f$N[d_1,\dots,d_n]~(n \geq 0)\f$ | A tensor of any shape. The element type \f$N\f$ may be any numeric type. |
            ///
            /// ## Output
            ///
            /// | Type                   | Description                                                                                                                                                             |
            /// | ---------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
            /// | \f$N[d_1,\dots,d_n]\f$ | The tensor \f$T\f$, where \f$T[i_1,\dots,i_n] = \mathit{op}(\texttt{arg}[i_1,\dots,i_n])\f$. This will always have the same shape and element type as the input tensor. |
            // clang-format on
            class UnaryElementwiseArithmetic : public Op
            {
            protected:
                /// \brief Constructs a unary elementwise arithmetic operation.
                UnaryElementwiseArithmetic();
                /// \brief Constructs a unary elementwise arithmetic operation.
                ///
                /// \param arg Node that produces the input tensor.
                UnaryElementwiseArithmetic(const std::shared_ptr<Node>& arg);
                /// \brief Constructs a unary elementwise arithmetic operation.
                ///
                /// \param arg Output that produces the input tensor.
                UnaryElementwiseArithmetic(const Output<Node>& arg);

                /// \brief Constructs a unary elementwise arithmetic operation.
                ///
                /// \param arg Node that produces the input tensor.
                UnaryElementwiseArithmetic(const std::string& node_type,
                                           const std::shared_ptr<Node>& arg);

            public:
                void validate_and_infer_types() override;
                bool is_unary_elementwise_arithmetic() const override { return true; }
            };
        }
    }
}
